With the continuous progress of industrialization process, the discharge of nitrogen-containing sewage is increased rapidly in China, which brings a great calamity to the environment, and particularly the treatment of some sewage with high ammonia nitrogen and low C/N ratio as generated in the industrial production gets wide attention from people. It is difficult for a conventional activated sludge process to meet the discharge standard during treatment of such sewage due to lack of carbon source. The biofilm process for sewage treatment forms a layer of active biofilm on a carrier after the sewage contained in the reactor comes into contact with the filler. The microorganisms mass-reproduced on the biofilm absorb and degrade the pollutants to achieve an effect of purifying the sewage, and since the biofilm has a strong tolerance, the biofilm process has a wide application prospect in treatment of sewage with a low C/N ratio. However, the biofilm culturing speed of the biofilm process still needs to be improved. Currently, the biofilm culturing manner mainly includes a “aerating process”, a “cycling process”, a “naturally biofilm culturing process”, and the like. The desired biofilm culturing time for each of these kinds of biofilm culturing processes is long, which often spends a time of 1-2 months. Chinese invention patent “biofilm culturing process on carrier filler of moving bed biofilm reactor” (publication No. 05565480A) performs water discharging and suspending of ion exchange sewage for a moving bed biofilm reactor at the same time to conduct a dynamic culture, and backflows the activated sludge. Such a method needs to control the sludge concentration and is inconvenient in operation, and the dynamic culture causes unstable running. Patent named as “Fast Biofilm Culturing Process of Microorganisms on Suspended Filler” (publication No. 05565480A) needs to run for 7-25 days to complete the biofilm culturing, and thus the time of biofilm culturing is still too long.
In the other hand, with the development of the industry of polymer synthetic material, a large number of organic polymer fillers have come out and applied, and become one of the most promising biofilm fillers. The types of commonly-used organic filler materials include polyethylene terephthalate (PET), polyvinyl acetal (PVF), polyacrylonitrile (PAN), polyamide (PA), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS) and the like. Therefore, it is of great practical significance to develop a fast biofilm formation method for an organic filler during treatment of sewage with a low C/N ratio and thus to speed up the start-up of the reactor.